This hard rock contains sand-sized grains of quartz. fractures cut across, not around the sand grains. what is the correct name for this rock?

The hard rock that contains sand-sized grains of quartz. fractures cut across, not around the sand grains is called schist. Schist is a medium-grade metamorphic rock with more than 50% platy and elongated minerals, like quartz and feldspar.

It can be found in many countries including Brazil, parts of the US and Ireland.